The goal of this project is to develop a computerized system to provide a foraging simulation to caged macaques. This is a basic technique (operant conditioning) that has been used with many species to investigate aspects of foraging decision-making, and the responses of animals to specific foraging conditions. We are interested in developing a system that can offer foraging opportunities that differ in the degree of predictability regarding the availability of food. For instance, one condition will represent a highly predictable food supply in which a quickly learned effort in responding to stimuli with a joystick would consistently produce a fixed reward, and another condition would provide a less predictable reward under similar circumstances. Our goal is to examine three aspects of the animal's responses 1) foraging decisions (when and how to expend energy in foraging), 2) the degree of psychological stress, if any, produced by these conditions, and 3) the degre e t o which such foraging challenges affect the psychological well-being of the animals. For the past several months we have been developing the apparatus (test cage, computer, reward dispenser, software), and we plan to begin testing the first subject in Spring 1999. FUNDING NIH grant RR00166.